Design for a bicycle gear shifter



FIG. 1 is a front elevation view of the bicycle gear shifter;

FIG. 2 is a left side elevation view;

FIG. 3 is a top plan view;

FIG. 4 is a rear elevation view;

FIG. 5 is a right side elevation view; and

FIG. 6 is a bottom plan view. 

The ornamental design for a bicycle gear shifter, as shown. 